U.S. Pat. No. 1,291,563 shows a shoe and glove buttoner having a pair of flared prongs for engaging a button, and a straight shank, there being a curve where the prongs join the shank to dispose the ends of the prongs at an angle to the shank.
U.S. Pat. No. 687,135 shows a collar buttoning device which has a spoon shaped end having a notch and wedge portion adjacent the spoon shaped end, and also having a shank. This device is used by inserting it through the button hole from the inside so that the flat shank easily enters the button hole and then the wedge portion spreads the button hole.
U.S. Pat. No. 1,306,790 shows a shoe buttoner having a shoe horn at one end, so that that transverse curve of the shoe horn provides stiffness. The shank is bent longitudinally near the lower portion to provide a curve portion.
U.S. Pat. No. 339,055 shows a boot buttoner with a bifurcated end which is bent slightly toward the shank.
German Patent 14,902 shows a boot buttoner in which a bifurcated end is disposed at an angle to a shank.
U.S. Pat. No. 178,778 shows a button hook with a bifurcated end which is bent away from the shank.